Post by on Jun 21, 2017 6:52:12 GMT

Here is an uncommon propellent combination that I was able to mostly find data on. The extremely unsafe chlorine trifluoride as an oxidizer with hydrazine fuel. Experimental engines using this propellent combination were built at some point, but were never used on a vehicle as far as I know.

I could not find bulk modulus or compressibility data for chlorine trifluoride.

The Chlorine Trifluoride Handling Manual has some interesting reading. It includes some information about material compatibility. It also has some chemical properties. Heat capacity is listed, but the English units suggest that it is specific heat (S).S = 0.303 Btu/lb-F = 1.268 kJ/kg-K = 1268 J/kg-Kwww.dtic.mil/dtic/tr/fulltext/u2/266121.pdf

The thermal conductivity (k) at 5.1 degrees C was calculated from Table 22 in this document. The temperature 5.1 degrees C was picked because it is below the boiling point and is still liquid.k = 0.111 Btu/hr-ft-F = 0.192 W/m-Kwww.dtic.mil/dtic/tr/fulltext/u2/512947.pdf

Post by on Jun 28, 2017 9:00:29 GMT

Bond dissociation energy (BDE) was estimated by adding up the bond energy of all the bonds. Bond energy is the average of the energy required to break a bond. This may differ from the actual energy required because BDE takes into account the individual bonds which may depend on the other bonds present. I used this chart for bond energy:www.sartep.com/chem/chartsandtools/bondenergy.cfmC-O 3*358C-C 4*347C=C 2*614C-H 5*413O-H 1*467total 6222

The report also compares WFNA hydrazine to WFNA furfuryl alcohol. I wish I had found this report earlier, since it seems to indicate a better value for WFNA hydrazine activation energy. The previous value from common-hypergolic-propellents is higher in comparison. This report suggests that WFNA hydrazine activation energy is closer to 5.16 kcal/mol, which is 21.6 kJ/mol. It would be nice to update the WFNA hydrazine reaction, but I guess that would need to be a suggestion for a patch eventually.

Chemical PropertiesMost of the chemical reaction was assumed to be the same as chlorine trifluoride and hydrazine. I estimated the activation energy using the entry for ClF5 in the NIST kinetics database. I used the higher activation energy value for ClF5, because it seemed to be measured under a wider range of temperatures.kinetics.nist.gov/kinetics/Search.jsp